Sluice type feeding device

ABSTRACT

A gravity feed device for a pneumatic material distributing system. The material is sluiced through a rubber hose by pinch rollers which move successively downward along the hose. The volume of the hose section between successive upper and lower rollers is increased by delaying the downward travel of the upper roller relative to the downward travel of the lower roller. Such volume increase protects sluiced granular material against crushing and jamming.

0 United States Patent [1 1 I 1 3,862,780

Senn Jan. 28, 1975 [54] SLUICE TYPE FEEDING DEVICE FOREIGN PATENTS ORAPPLICATIONS lnvemofi Georg Sen", Mutschellenr 588,154 5/1947 GreatBritain 302/49 Switzerland 949,998 9/1956 Germany 302/49 [.73] AssigneezSp bag A g e c a t, 73l,037 3/1966 Canada 302/49 Widen-Mutschellen,Switzerland Primary ExaminerRichard A. Schacher [22] Flled: July 1974Assistant Examiner-W. Scott Carson 21 Appl 491 7 Attorney, Agent, orFirm-James E. Nillcs [30] Foreign Application Priority Data ABSTRACTJuly 27, 1973 Switzerland 10966/73 A gravity feed device for a pneumaticmaterial distrib- Y uting system. The material is sluiced through arubber U.S. hose pinch rollers which move successively down. 417/477ward along the hose. The volume of the hose section Int. Cl. betweensuccessive upper and lower roners is in- Field of Search 42, 52, 62,creased by delaying the downward travel of the upper 5' roller relativeto the downward travel of the lower roller. Such volume increaseprotects sluiced granular References Cited material against crushing andjamming.

UNITED STATES PATENTS 3,523,000 8/1970 Miller 417/477 8 Clams 9 Drawmgfigures PATENIEI] JAN 2 8 I975.

SHEET 1 BF 3 PATENTED 3,862,780

sum 2 BF 3 Fig. 7

PATENTEB JAN 2 8 I975 SHEET 3 BF 3 1 SLUICE TYPE FEEDING DEVICEBACKGROUND OF THE INVENTIQN The invention relates to a sluice typefeeding device for material distributing systems and it is concernedmore particularly with the provision of an improved device for sluicingmaterial into distributing systems which are pressurized in order toadvance the material received from the feeding device. To that end theinvention contemplates the provision of an inclined rubber elastic hoseor a plurality of such hoses arranged side by side, and the provisionofa plurality of pinch elements which are circulated by an endless drivemechanism so as to provide travelling constrictions along the hose.

Pressure sluices have heretofore been known wherein flexible wallportions are provided by means of a flexible hose. Such flexible hose iscompressed by roI-' lers which are connected to a chain drive. Thesuccessive clamping rollers alternately form one or two travellingconstrictions as they are guided along the hose.

In prior art pressure sluices of this type the hose volume between twoconstrictions remains constant and is completely filled by the materialto be sluiced. That means that when the rollers bear upon the hose theycompress and damage the material therein. On the other hand, the hosecannot be sealed tightly at the constrictions because of the interveningmaterial, and the pressure sluice will be leaking.

The heretofore known devices of the mentioned type also have thedisadvantage that they are either leaky, or become jammed in operationor can only be used for certain products.

SUMMARY OF THE INVENTION Generally the invention provides an improvedsluicetype feeding device which overcomes the hereinbefore mentioneddisadvantages and shortcomings of the prior art.

More specifically, the improved feeding device incorporating theinvention comprises two successive hose pinching elements which define achamber in the associated hose or hoses and whereby the volume of saidchamber is increased during the period between its formation and itsdischarge in order to insure tight sealing of the chamber by the secondpinching element following the first.

DRAWINGS The foregoing and other objects and advantages of the inventionwill become more fully apparent as this disclosure proceeds withreference to the accompanying drawings, wherein:

FIGS. 1-5 are side elevations of a device incorporating the inventionand illustrating various phases of operation;

FIG. 6 is a rear view of the device from which the backing wall for thehose has been removed;

FIG. 7 is a partial view of the device according to FIG. 6 with thecontrolled chain tensioning bracket in the position according to FIG. 2;

FIG. 8 is an enlarged perspective view of a modified detail ofconstruction; and

FIG. 9 is an enlarged perspective view of a portion of connecting hoseof the device shown in FIGS. l-(r.

DETAILED DESCRIPTION The sluice type feeding device is enclosed within ahousing 1 which carries a material inlet funnel 3. Underneath is apneumatic material distributing system which has an attaching stud 7. Aconnecting hose 9 connects the outlet of the funnel 3 with the attachingstud 7 of the pneumatic distributing system 5. At the rear side of thedistributing system the hose 9 is backed by an abutment wall] I. Thehose 9'is provided with a pressure equalizing passage 13 whosefunctionwill be explained later. The moving part of the device includes a chaindrive IS with a driving sprocket 17 which is carried on a shaft 18 anddriven by a power unit I9 (FIG. 6). The chain drive further includes anupper chain sprocket 21. A duplicate chain drive 28 which is spacedlaterally from and extends parallel to the chain drive 15 comprises adrive sprocket 30 and an upper chain sprocket 32. Arranged between thetwo chain drives 15 and 28 are four idlers 23, 24, and 26. The rollers23-26 are connected by associated drag lugs with the two chain drives 15and 28. They are guided on roller guide tracks 34 and 35. As may be seenfrom FIG. 7, the rollers 23-26 may be guided on the tracks 34, 35 byball bearings. A controlled chain tensioning bracket 37 is rockablysupported on a stationary pin 39. The chain tensioning bracket comprisesa first tensioning arm 41 having a stud 42 and a sprocket 43 thereon incooperative engagement with the chain of the associated chain drive 15or 28. A second chain tensioning arm 45 is rigidly connected with thefirst chain tensioning arm 41 and in turn has a stud 46 and sprocket 47thereon which like sprocket 43 cooperates with the chain of theassociated chain drive. The two tensioning arms 41 and 45 areinterconnected in such a manner that upon rocking of the bracket 37 thetwo rearward chain stretches next to the hose 9 or, alternately, theforward two chain stretches are tensioned, and the remaining chainstretches are correspondingly relieved. Actuation of the chaintensioning bracket 37 is effected by a cam disc 49 on the shaft 18.

The housing I surrounds an interior space 51 which may be depressurizedthrough an evacuating connection 52. When this is done the interiorpressure within the hose 9 will become effective after each hosepinching travel of a roller to restore the hose to its roundedconfiguration and thereby insure filling of the latter with materialfrom the funnel 3. In FIGS. I-5 the funnel 3 holds supply material 54;the hose 9 as well as a chamber formed by one or two of the rollers23-26 hold supply material 55, and the distributing system 5 containssupply material 56.

It is necessary to position the device in such a manner that the supplymaterial falls under its own weight from the funnel 3 through theconnecting hose 9, and the rollers 23-26 therefore actually serve assluicing elements rather than as propelling elements as they functiondefinitely in the case of hose pumps. In this manner it is possible tointroduce any kind of material and particularly granular material intopneumatic distributing systems which are pressurized at the materialinlet station and which therefore absolutely require a good, tight sealfor the sluicing injection of the supply material.

The herein disclosed sluice type feeding device operates as follows:

In the first phase (FIG. I) the supply material 54 falls freely from thefunnel 3 into the connecting hose 9 to the height of the roller 23. Atthe same time the downwardly moving pinch roller 23 produces a certainsuction effect upon the material within the funnel 3.

In the second phase (FIG. 2) the free end of the controlled chaintensioning bracket 37 engages the hump of the cam disc 49 and rocks thebracket 37 clockwise on the stationary pin 39. As a result, the firsttensioning arm with the sprocket 43 thereon draws the associatedrearward chain stretch against the upper chain sprocket 21 as shown inFIG. 2 and as also illustrated by FIG. 7. Analogously the second chainstretch which is synchronized with the first chain stretch is drawnagainst the upper chain sprocket 32. Correspondingly, the second chaintensioning arms 45 with the sprockets 47 thereon relieve the two forwardchain stretches whereby the first tensioning arms 41 are permitted tomove. Due to this movement the spacing between the rollers 23 and 26 isdecreased.

The third phase is illustrated by FIG. 3. The roller 26 moves intocontact with the connecting hose 9 and compresses the latter. At thesame time the free end of the first tensioning arm 41 slips from thehump of the cam disc 49 and a tensioning spring, not shown, restores thechain tensioning bracket 37 to its original FIG. 1 position. The spacingbetween the rollers 23 and 26 now increases and resumes its normallength. Within the chamber of the hose 9 which extends between the tworollers an air cushion 59 develops whereby the material within the hose9 is protected against damage and congestion during the continuedmovement of the roller 26.

During the further travel of the rollers (Phase 4, FIG. 4) the aircushion 59 moves into communication with the pressure equalizing passage13 which isconnected by a suitable tube such as the tube 13a shown inFIG. 8 with the pneumatic distributing system 5. This provides for anequalization of the pressure at the material inlet of the pneumaticdistributing system and the pressure within the hose chamber between therollers 23 and 26.

In the next phase (FIG. 5) which corresponds to phase 1 (FIG. 1) theroller 23 opens the connecting hose 9 and the supply material fallsunder its own weight through the rest of the hose and through theattaching stud 7 into the piping of the pneumatic distributing system 5.At the moment when the hose is opened by the roller 23 the upper roller26 must already have reclosed the hose to prevent the pressure withinthe pneumatic distributing system 5 from leaking upward through the hose9 into the funnel 3. The material which has dropped into thedistributing system 5 is conveyed pneumatically to its destination.

As has already been pointed out hereinbefore, the herein discloseddevice is not a pumping device but rather a sluice type feeding device.Hose pumps are not suitable for the intended purpose except for handlingmedia that lend themselves to pumping, that is, liquid or paste-likesubstances. Such pumps cannot be used for granular or solid materials.On the other hand, according to the invention, the material is fed intoan inclined hose so that it is actually conveyed by its own weight.However, care must be taken to provide sufficient room within the hosefor the incoming material so that it will not be jammed during thesubsequent pinching of the hose. This is accomplished according to theinvention by delaying the movement of the upper pinch roller withrespect to the movement of the lower pinch roller and thereby increasingthe volume of the hose chamber between the successive pinch rollers anddeveloping an air cushion in the upper part of said chamher.

In principle, it would also be possible to increase the volume of thehose section between successive pinch rollers by installing a downwardlyflaring hose, as for instance a conical hose 90 (FIG. 8), between thefunnel 3 and the attachment stud 7. In that case the velocity of thesuccessive pinch rollers could be kept constant. In this manner it wouldbe possible to develop the absolutely necessary air cushion, such as theair cushion 59 shown in FIG. 4.

Before the material passage from the connecting hose 9 to the pneumaticdistributing system is established the pressure in the hose should beraised to a value which ideally should be equal to or even somewhathigher than the pressure in the distributing system 5. This isaccomplished by the mentioned pressure equalization via the attachmentstud 7. If this were not done the higher pressure in the distributingsystem 5 would cause the material in the hose 9 to be pushed back andunder the upper pinch roller.

By reason of the mentioned evacuation of the space 51 which insures fullexpansion of the hose 9, the degree of filling the hose 9 can beoptimized. The space 51 is preferably evacuated to a pressure of, forinstance, 0.6 ata. This is absolutely necessary if for pur pose ofhighoutput capacity high velocities of the devices and pinch rollers areincurred.

It is also possible to provide several funnels and several hoses side byside and to operate the hoses by the same but wider pinch rollers. Suchan arrangement could be used, for instance,.for the mixing ofcomponents.

The requirements for the connecting or sluicing hose 9 (FIGS. 1-6) and9a (FIG. 8) are severe. The hose must be soft, flexible and wearproofand yet it must be able to withstand pressure and be stretchprooflengthwise. The core 912 (FIG. 9) consists of thick walled, wearproofand soft rubber and is fabric reinforced lengthwise. The lengthwisereinforcement 60 (FIG. 9) prevents downward displacement of the hose 9or 9a while it is acted upon by the pinch rollers. Due to the absence ofcross reinforcement the core remains readily pinchable. However, it isnot pressure resistant. For that reason, a second, thin walled fabrichose having crosswise and lengthwise reinforcements 62 and 64,respectively, is pulled over the thick walled flexible core 9b. The corehas some clearance within the fabric hose 9c. As a result, noobjectionably high tension stresses are developed in the fabric hoseduring the pinching, so that thelife of the hose will be considerablyprolonged.

As distinguished from cell wheel sluices and rotor systems the presentinvention provides a closed system. There are no rotary seals which comeinto contact with the supply material. Consequently, the powerrequirement will be low and wear can be reduced to a minimum. No dust isproduced which is passed by leakage air upward into the funnel oroutward through defective seals.

The device may be equipped with a funnel for operating it or it may beflanged directly to a silo. It is capable to sluice dry material ofpowderlike up to coarse grained consistency. In connection with bowltype mixing equipment moist to wet materials may be handled.

Due to the volume controlled dosing of the material by the pinch rollersa continuous feed is obtainable which permits direct spraying of theemitted conveyed materials.

l claim:

1. A sluice type feeding device for pneumatic material distributingsystems comprising at least one compressible conveying hose, a pluralityof successive pinch elements cooperable with said hose to define amaterial confining chamber therein between an upper and lower of saidpinch elements, and drive means for said pinch elements operable toincrease the volume of said chamber as said pinch elements move alongsaid hose.

2. A sluice type feeding device as set forth in claim 1 wherein saidconveying hose has a downwardly flaring configuration.

3. A sluice type feeding device as set forth in claim 1 wherein aplurality of rollers forming said pinch elements are mounted on a pairof endless chain drives for movement along said conveying hose, andwherein tensioning means for said chain drives are operable to elongateone pair of chain stretches of said drives while simultaneouslyshortening the other pair of chain stretches of said drives.

4. A sluice type feeding device as set forth in claim 3 wherein saidtensioning means for said chain drives comprise a double armed leversystem which is rockable selectively in opposite directions about afixed pivot element, rocking of said lever system in one direction beingeffective to elongate one pair of chain stretches of said drives whilesimultaneously shortening the other pair of chain stretches of saiddrives, and rocking of said lever system in the other direction beingeffective to shorten said one pair of chain stretches of said driveswhile simultaneously elongating said other pair of chain stretches ofsaid drives.

5 A sluice type feeding device as set forth in claim 4 and furthercomprising cam means operable by said chain drives to rock said doublearmed lever system.

6. A sluice type feeding device as set forth in claim 3 and furthercomprising guide tracks for said pinch rollers.

7. A sluice type feeding device as set forth in claim 1 and furthercomprising pressure equalizing means operatively interposed between saidmaterial confining chamber of said conveying hose and an associatedpneumatic material distributing system.

8. A sluice type feeding device as set forth in claim 1, wherein saidconveying hose comprises a tubular,

elastic core and a lengthwise fabric reinforcement thereof, and an outercrosswise and lengthwise reinforced fabric hose surrounding said core.

1. A sluice type feeding device for pneumatic material distributingsystems comprising at least one compressible conveying hose, a pluralityof successive pinch elements cooperable with said hose to define amaterial confining chamber therein between an upper and lower of saidpinch elements, and drive means for said pinch elements operable toincrease the volume of said chamber as said pinch elements move alongsaid hose.
 2. A sluice type feeding device as set forth in claim 1wherein said conveying hose has a downwardly flaring configuration.
 3. Asluice type feeding device as set forth in claim 1 wherein a pluralityof rollers forming said pinch elements are mounted on a pair of endlesschain drives for movement along said conveying hose, and whereintensioning means for said chain drives are operable to elongate one pairof chain stretches of said drives while simultaneously shortening theother pair of chain stretches of said drives.
 4. A sluice type feedingdevice as set forth in claim 3 wherein said tensioning means for saidchain drives comprise a double armed lever system which is rockableselectively in opposite directions about a fixed pivot element, rockingof said lever system in one direction being effective to elongate onepair of chain stretches of said drives while simultaneously shorteningthe other pair of chain stretches of said drives, and rocking of saidlever system in the other direction being effective to shorten said onepair of Chain stretches of said drives while simultaneously elongatingsaid other pair of chain stretches of said drives.
 5. A sluice typefeeding device as set forth in claim 4 and further comprising cam meansoperable by said chain drives to rock said double armed lever system. 6.A sluice type feeding device as set forth in claim 3 and furthercomprising guide tracks for said pinch rollers.
 7. A sluice type feedingdevice as set forth in claim 1 and further comprising pressureequalizing means operatively interposed between said material confiningchamber of said conveying hose and an associated pneumatic materialdistributing system.
 8. A sluice type feeding device as set forth inclaim 1, wherein said conveying hose comprises a tubular, elastic coreand a lengthwise fabric reinforcement thereof, and an outer crosswiseand lengthwise reinforced fabric hose surrounding said core.